Work

Effect of Mineral Nutrient Sprays on Photosynthesis and Stomatal Opening of Water-stressed and Unstressed Apple Seedlings II. Potassium Sulfate Sprays1

Year: 1982

Type: article

Abstract: ‘York Imperial’ apple seedlings ( Malus domestica Borkh.) grown in nutrient solution cultures with decreased water potential to− 1.0 bar by polyethylene glycol (PEG) increased water consumption, photosynthesis rate (P n ), and stomatal conductance (C s ). High light preconditioning of the plants used in this experiment was probably the reason why− 1.0 bar water potential in the nutrient solution was not low enough to induce apple seedling responses typical of water-stressed plants. However, application of PEG stress (−1.0 bar), to K-sprayed (K 2 SO 4 , −0.5%) trees lowered seedling water consumption Pn, and C s . Potassium sprays alone did not significantly affect water consumption, Pn or C s . When the water potential of the nutrient solution of PEG stressed plants was further decreased to −2.5 bars, unsprayed trees started to wilt within 2 days while sprayed trees did not. It is proposed that earlier stomatal closure of K-sprayed trees when stressed, already at low level of water stress (−1.0 bar), prevented plant water depletion when stress level was increased. This in turn delayed commencement of plant wilting. Potassium sprays also increased root:shoot ratio and root K concentration in PEG-stressed plants. These responses of K-sprayed trees could also contribute to greater tolerance to higher levels of water stress.

Source: Journal of the American Society for Horticultural Science

DOI: 10.21273/jashs.107.4.568

Authors: Dariusz Swietlik, R. F. Korcak, Miklos Faust

Institutions: Agricultural Research Service, Beltsville Agricultural Research Center

Language: English

Topic: Plant Stress Responses and Tolerance

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: hybrid

Estimated APC paid: $3,500